<!DOCTYPE html>
<style>
  /* These are children with negative block sizes. Absolute values are chosen
     large enough compared to math layout constants. */
  span { display: inline-block; }
  mspace, span {
    margin-block-start: -10em;
    margin-block-end: -10em;
  }
  /* Override display: none; from UA style sheet for the following children. */
  maction > :not(:first-child),
  semantics > annotation,
  semantics > annotation-xml {
    display: math;
  }
</style>
<math>
  <mi><span></span></mi>
  <mn><span></span></mn>
  <mo><span></span></mo>
  <ms><span></span></ms>
  <mtext><span></span></mtext>
</math>
<math>
  <semantics>
    <mspace/>
    <annotation><span></span></annotation>
    <annotation-xml><span></span></annotation-xml>
  </semantics>
</math>
<math>
  <mtable>
    <mtr>
      <mtd><mspace/></mtd>
      <mtd><mspace/></mtd>
      <mtd><mspace/></mtd>
    </mtr>
    <mtr>
      <mtd><mspace/></mtd>
      <mtd><mspace/></mtd>
      <mtd><mspace/></mtd>
    </mtr>
  </mtable>
</math>
<math>
  <mspace/>
  <mspace/>
  <mspace/>
  <mspace/>
</math>
<math>
  <maction>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </maction>
  <merror>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </merror>
  <mpadded>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </mpadded>
  <mphantom>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </mphantom>
  <mstyle>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </mstyle>
</math>
<math>
  <mfrac>
    <mspace/>
    <mspace/>
  </mfrac>
  <mfrac linethickness="0">
    <mspace/>
    <mspace/>
  </mfrac>
</math>
<math>
  <msqrt>
    <mspace/>
    <mspace/>
    <mspace/>
    <mspace/>
  </msqrt>
  <mroot>
    <mspace/>
    <mspace/>
  </mroot>
</math>
<math>
  <msup>
    <mspace/>
    <mspace/>
  </msup>
  <msub>
    <mspace/>
    <mspace/>
  </msub>
  <msubsup>
    <mspace/>
    <mspace/>
    <mspace/>
  </msubsup>
  <mmultiscripts>
    <mspace/>
    <mspace/>
    <mspace/>
    <mprescripts/>
    <mspace/>
    <mspace/>
  </mmultiscripts>
</math>
<math>
  <mover>
    <mspace/>
    <mspace/>
  </mover>
  <munder>
    <mspace/>
    <mspace/>
  </munder>
  <munderover>
    <mspace/>
    <mspace/>
    <mspace/>
  </munderover>
</math>
